var foo = 'bbb'

// console.log(exports)

exports.foo = 'hello'

exports.add = function (x, y) {
    return x + y
}

exports.readFileee = function (path, callback) {
    console.log('文件路径:', path)
}

var age = 18 // 作废  a.js引入不了

exports.age = age

function add (x, y) { // 作废  a.js引入不了
    return x - y
}